Angiofibroma refers to a non-cancerous growth composed of blood vessels and fibrous connective tissue. They typically appear as small, reddish bumps on the skin, often on the face. Angiofibromas can pose challenges depending on their size and location within the body.
Understanding Angiofibromas
Angiofibromas are benign vascular neoplasms. These growths can cause issues due to their potential for growth and their location. Histologically, angiofibromas are characterized by a proliferation of stellate and spindle cells, along with thin-walled blood vessels that have dilated lumens, all set within a dense network of collagen bundles in the dermis.
The most common types of angiofibromas include nasopharyngeal angiofibromas and facial angiofibromas. Nasopharyngeal angiofibromas, also known as juvenile nasopharyngeal angiofibromas (JNAs), arise from the back of the nasal cavity. These are almost exclusively found in adolescent males. Facial angiofibromas are often associated with Tuberous Sclerosis Complex (TSC) and commonly appear on the central face, including the nose and cheeks.
Recognizing Symptoms
The symptoms associated with angiofibromas vary considerably based on their specific location and size. For nasopharyngeal angiofibromas, common indicators include recurrent nosebleeds, which can be frequent and challenging to stop. Individuals may also experience nasal obstruction.
As nasopharyngeal angiofibromas grow larger, they can cause facial swelling, persistent headaches, and changes in voice. If the tumor expands into adjacent areas like the eye orbit or cranial cavity, more severe symptoms may develop. Facial angiofibromas primarily manifest as skin lesions. These typically appear as small, firm, reddish or flesh-colored papules, often clustered in the butterfly region across the nose and cheeks.
Causes and Development
The precise causes of nasopharyngeal angiofibromas are not fully understood, but several factors are thought to contribute to their development. Hormonal influences are believed to play a role, as these tumors occur almost exclusively in adolescent males. Studies have identified androgen, progesterone, and estrogen receptors within the tumor tissue, suggesting that the increase in androgen levels during puberty may stimulate tumor growth and vascular expansion.
Genetic predispositions are also considered, with some research indicating associations with chromosomal abnormalities, such as deletions on chromosome 17, and altered gene expressions, including the APC gene. Facial angiofibromas are strongly linked to genetic mutations associated with Tuberous Sclerosis Complex (TSC). This genetic disorder results from mutations in either the TSC1 or TSC2 genes, which are responsible for producing proteins that regulate cell growth and division. These mutations lead to uncontrolled cell proliferation and the formation of benign growths in various organs, including the skin. Angiofibromas are not contagious, nor are they caused by lifestyle choices.
Diagnosis and Management
Diagnosing angiofibromas involves a thorough clinical evaluation and advanced imaging techniques. For suspected nasopharyngeal angiofibromas, a physical examination, often including a nasal endoscopy, can reveal the presence of a mass within the nasal cavity. Imaging studies such as CT scans and MRIs are then performed to determine the precise size, location, and extent of the tumor, as well as any invasion into surrounding structures like the sinuses, skull, or brain.
Biopsy is generally avoided for nasopharyngeal angiofibromas due to their highly vascular nature, which carries a substantial risk of severe bleeding. Instead, diagnosis relies heavily on the characteristic findings from imaging and the patient’s clinical presentation. Angiography, an imaging technique that visualizes blood vessels, is often used pre-operatively to map the tumor’s blood supply, particularly the feeding vessels from the external carotid system, such as the internal maxillary artery.
The primary treatment for nasopharyngeal angiofibromas is surgical excision. To minimize bleeding during surgery, pre-operative embolization is commonly performed. This procedure involves injecting a substance into the blood vessels supplying the tumor to block them, thereby reducing blood flow. In cases where complete surgical removal is not feasible or if the tumor recurs, radiation therapy may be considered.
For facial angiofibromas, treatment options often focus on cosmetic improvement and symptom management. Topical medications, such as mTOR inhibitors like sirolimus cream, can be applied to reduce the size and redness of the lesions. Laser therapy, particularly carbon dioxide (CO2) laser ablation, is also an effective method to vaporize these skin lesions. Systemic mTOR inhibitors may be prescribed for severe cases or when angiofibromas are part of a broader Tuberous Sclerosis Complex manifestation. A multidisciplinary approach involving various specialists is often employed to provide comprehensive care.